論文選擇極化碼作為研究主題使用的通道編碼。研究主要設計了空間交錯以及HARQ兩種方式，欲改善極化碼在有限長度時的錯誤率表現。空間交錯方法是將訊息區塊以modulo-2加法產生具關連性的訊息完成極化碼編碼，再以設計的交錯架構解碼方式來對極化碼進行解碼。HARQ方法設計概念類似空間交錯，傳送端以modulo-2加法來生成極化碼資訊位元部分，接收端則以LDPC解碼概念所設計的方式來對極化碼進行解碼。
模擬結果發現對於空間交錯方法而言，增加架構解碼的運算有利於空間交錯方法的表現，使得其錯誤率能夠優於原本的極化碼。HARQ方法跟原本極化碼的比較，除了錯誤率表現還要比較傳輸效率。從模擬結果發現HARQ方法的解碼方式設計存在著錯誤蔓延的問題，會導致錯誤率表現並不如原始的極化碼。

In this paper, spatial coupling and HARQ techniques are used to improve the error-correcting performance of finite length polar codes. Polar codes are considered as base codes. For the spatial-coupling method, multiple polar codes are associated by combining message bit blocks of adjacent coupling positions with modular-two addition. The design of HARQ method has the similar idea of spatial-coupling method. HARQ transmitter uses modular-two addition to combine message bit blocks for polar codes. HARQ reciver uses a way to decode the designed spatial-coupling structure.
Simulation results show that, with a little extra operation complexity, spatially coupled polar codes can provide better error-correcting performance than original polar codes. For HARQ method, it compares the error performace and throughput efficiency with original polar codes. Because of the error propagation problem of the decoding design, HARQ method can not provide better performance than original polar codes.

第1章 緒論 1
1.1 研究背景 1
1.2 研究目的 1
第2章 極化碼回顧 3
2.1 通道極化 3
2.1.1 通道結合 3
2.1.2 通道分解 5
2.2 極化碼編碼 6
2.2.1 資訊位元與凍結位元 7
2.2.2 編碼 9
2.3 極化碼解碼 11
2.3.1 Successive Cancellation (SC) 解碼器 11
2.3.2 List Successive Cancellation (List-SC) 解碼器 12
2.3.3 Belief Propagation (BP) 解碼器 13
2.3.4 Soft Cancellation (SCAN) 解碼器 15
2.3.5 解碼器比較 19
第3章 空間交錯方法 20
3.1 空間交錯編碼 20
3.2 空間交錯解碼 22
3.3 模擬結果 25
第4章 HARQ方法 30
4.1 HARQ設計 30
4.2 HARQ解碼 32
4.3 模擬結果 34
第5章 結論 41
參考文獻 42
附 錄 44

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